We received the following report via bugtraq.
The issue is public.

Looks like we missed these:

Date: Fri, 28 Jan 2005 23:09:03 -0600 (CST)
From: Jonathan Angliss <jon@squirrelmail.org>
To: bugtraq@securityfocus.com
Cc: security@squirrelmail.org
Subject: SquirrelMail Security Advisory

SquirrelMail Security Advisory
==============================

SquirrelMail 1.4.4 has been released to resolve a number of security
issues disclosed below.  It is strongly recommended that all running
SquirrelMail prior to 1.4.4 upgrade to the latest release.

Remote File Inclusion
---------------------
Manoel Zaninetti reported an issue in src/webmail.php which would allow a
crafted URL to include a remote web page.  This was assigned CAN-2005-0103
by the Common Vulnerabilities and Exposures.

Cross Site Scripting Issues
---------------------------
A possible cross site scripting issue exists in src/webmail.php that is
only accessible when the PHP installation is running with register_globals
set to On.  This issue was uncovered internally by the SquirrelMail
Development team. This isssue was assigned CAN-2005-0104 by the Common
Vulnerabilities and Exposures.

A second issue which was resolved in the 1.4.4-rc1 release was uncovered
and assigned CAN-2004-1036 by the Common Vulnerabilities and Exposures. 
This issue could allow a remote user to send a specially crafted header
and cause execution of script (such as javascript) in the client browser.

Local File Inclusion
--------------------
A possible local file inclusion issue was uncovered by one of our
developers involving custom preference handlers.  This issue is only
active if the PHP installation is running with register_globals set to On.


It is strongly suggested that all users running SquirrelMail prior to
1.4.4 upgrade to the latest release.  Those using a development release,
should upgrade to the latest snapshots to ensure they have the latest
updates for these issues.  A full list of changes in this, and previous
releases can be found here (http://www.squirrelmail.org/changelog.php).

For further updates on security issues, details are posted to
http://www.squirrelmail.org/security/.  Any security issues should be
emailed to security@squirrelmail.org.

We'd like to express thanks for those that have worked with us on getting
security issues resolved with SquirrelMail, and hope that people continue
to do so in such fashion, it is much appreciated.

-- 
Jonathan Angliss
SquirrelMail Development Team